4.14 Collision Detection and Physics

This section presents everything about collision detection and physics.

The first sub-section presents the collision system
of Crystal Space, that allows to test for collisions between meshes and entities,
as well as to control the motion of collision actors that will move around the
scene depending on the collisions with the objects in it.

The physical simulation goes a step further than simple collision tests, by allowing
to animate the objects depending on the simulation of the forces that are applied on
them.

There are two plugins for the physical simulation, based respectively on the
Bullet and the ODE
libraries. The ODE library is one of the first open source library for physical
simulation, and has been a reference for a long time, being used in many games and
simulation environments. But these last years it has been overtaken by Bullet which
is now far more widely used and has more features such as soft bodies, terrains and
kinematic objects.

This is not advised anymore to use the ODE plugin, in most
cases, the Bullet plugin will be more interesting.

Lastly, it has to be mentioned that both the collision and physical frameworks, that
are separated until now, are currently being merged in a common framework. This work
is however not yet available in the release V2.0 of Crystal Space.